The difference is that Coan has a lifetime ban due to multiple drug test fails. As he said in a podcast, no one knew how long it took for Deca to clear from your system (that's not word for word quote, just a summation).
The other guy had a drug ban which he served out. (You don't get a lifetime ban for a first time fail and often, depending on the offence, don't get a full 4 year ban.) It may have been a short ban, such as being pinged for a stimulant, but not sure. Either way, as I said, you don't get a permanent ban for your first fail. Just like in the justice system where a first time offender does not normally get the full sentence. Anyhoo, he did the crime and did the time. He is now back competing and would be a sure target for repeat tests, win or lose.
I don't see a problem with PA's rules (same as IPF rules) at all. It's not like PA is the only fed around. If you want to do stuff that's against the rules, just join anyone else who allow anything and everything. You know, no drug testing, monolift, wraps counting as raw, shitting judging, multiply, thin bendy deadlift bars, etc. That's what Chleo Van Wyk did.